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Medical Cannabis for the Treatment of Dementia: A Review of Clinical Effectiveness and Guidelines

Last updated: July 17, 2019
Project Number: RC1152-000
Product Line: Rapid Response
Research Type: Drug
Report Type: Summary with Critical Appraisal
Result type: Report


  1. What is the clinical effectiveness of medical cannabis for the treatment of dementia?
  2. What are the evidence-based guidelines associated with the use of medical cannabis for the treatment of dementia?

Key Message

Limited evidence from one systematic review3 and one uncontrolled before-and-after study10 suggested that medical cannabis may be effective for treating agitation, disinhibition, irritability, aberrant motor behaviour, and nocturnal behaviour disorders as well as aberrant vocalization and resting care, which are neuropsychiatric symptoms associated with dementia. There was also limited evidence of improvement in rigidity and cognitive scores as assessed by Mini-Mental State Examination. The evidence from the systematic review came from four of its primary studies, whereas its remaining eight included studies did not find favourable or unfavourable evidence regarding the effectiveness of cannabinoids in the treatment of dementia. Sources of uncertainty included the low quality of evidence in the primary studies of the systematic review3 and the fact that the uncontrolled before-and-after study10 was a nonrandomized pilot study in 10 dementia patients that reported descriptive outcomes without statistical analysis. No relevant evidence-based clinical guidelines regarding the use of medical cannabis for treating dementia were identified.